Portable mortise and tenon machine



June 21, 1932. A. E. MITCHELL PORTABLE MORTISE AND TENON MACHINE FiledMarch 4, 1932 4 Sheets-Sheet 1 [N VENTOR .4 TTORNEY June 1932- A. E.MITCHELL 1,863,605

PORTABLE MORTISE AND TENON MACHiNE Filed March 4, 1932 4 Sheets-Sheet 2[N VENTOR.

Mugs

ATTORNEY June 21, 1932. E, MlTcHELL 1,863,605

PORTABLE MORTISE AND TENON MACHINE Filed March 4. 1932 4 Sheets-Sheet 31N VENTOR M m imzzze ATTORAEV June 21, 1932. E, MW HE LL 1,863,605

PORTABLE MORTISE AND TENON MACHINE Filed March 4, 1952 4 Sheets-Sheet 411v VENTOR ATTORNEY Patented June 21 1932 UNITED. STATES ALBERTMITCJEIELL,

STAMFORD QQNNECTIGUT PORTABLE MQBTISE AND TENON MACHINE Applicationfiled March 4,

This invention relates to portable machines for reforming damagedmortise or tenon ends on underground conduit sections.

Underground conduits are made up of square wooden sections ranging inlength from three to ten feet or over and are provided with a centralbore extending the entire length of the said sections, and each sectionis provided with-a tenon and mortise and concentric with the saidcentral bore,

the tenon end of one section fitting into the mortise end of thenext'section'in a given conduit.

In shipping the conduit sections or in the 1.5 handling of same in thefield, the tenon end which is comparatively frail becomes damaged. Attimes the mortise end also becomes damaged. Up to'the present time thedamaged tenon has been reformed by acarpenter with a saw and chisel andthe mortise end, by anymeans found practical.

The reforming of the said ends by the means referred to is costly andtakes up a great deal of time. In'order to obviate the disadvantages ofthe present method of reforming the said ends, I have perfected myinvention.

One object of the invention is to provide a portable hand machine withwhich the damaged mortise and tenon ends of conduit sections mayaccurately and rapidly be reformed in the field. V

Another object of the invention is to provide a machine of thischaracter havinga holding vise which will accomodate various sizes ofconduit sections and to have sufiicient side movement to be'able toperfectly aline the work with the vertical center line of the machine.

A further object of the invention is to provide a tool carrying discadapted to be rotated and fed inwardly of the work either due to thesaid rotation or independently thereof. I V

Another object is to produce a device of the character described inwhich the maximum simplicity of construction and operation is secured. e

Other objects and advantageswill appear as the nature of theimprovements i better 1932. Serial No. 596,682.

understood, the invention consisting sub.- stantially in the novelarrangement and co? relation of parts herein fully described, andillustrated in the accompanying drawings, wherein similar referencecharacters are used to describe corresponding parts throughout theseveral views, and then finally pointed out and specifically defined andindicated in the,

appended claims. e

The disclosure made the basis of exemplifying the present inventiveconcept suggests a practical embodiment thereof, but

the invention is not to be restricted to the exact details of thisdisclosure, and the latter, therefore, is to be understood from anillus: trative, rather ,than arestrictive standpoint.

The inventive idea involved is capable of receiving a variety ofmechanical expressions, one of which, for the purpose of illus-..

tration, is shown in the accompanying drawings, in which- Figure 1 is anend view in elevation of the work receiving end of one form of themachine. Y

Figure 2 is a side view thereoflooking from the right of Figure 1. r

Figure 8 is a sectional view taken on line 33 Figure l. 1 i V Figure 4is a fragmental view in elevatinn of the end oppositethat shown inFigure 1 of a modifiedform of the invention. Figure 5 is a top .planview thereof. Figure 6 is a side view thereof, looking from the left ofFigure 4. K

Figure 7 is a perspectiveview of. the grooving tool.

Figure 8 is a front View of the tool carry-- ing disc, and

Figure 9 1s a perspective view partly broken away, of a conduit section.

Referring now to the drawings in detail 7 and ore particularly toFigures 1, .2, 3," Z, 8 and of the said drawings 20 indicat base boardor'support, to whichis' by means of bo1tsf21 a bracket 2 2 h bosses orbearings '23 throughwhieh' pass bolts 24 upon each of whichthere'ispivotally mounted apairof links25; Inferiiie diate the ends ofeach pair of the said links 25, as at 26 tliere is pivotally mounted avise each other when the screw 36 is turned by jaw 27 having two sidesat right angles to each other adapted to receive a conduit section 28which is to be reformed.

The links at the right side of the machine looking at Figure 1 are.pivotally connected at their upper ends by means .of screw threadedplugs 30, and .nuts 31, the said plugs extending from each side of ablock 32 provided with a centrally located opening 33 having an internalleft hand thread therein. The links 25 at the left hand side of themachine are similarly connected to a block 34 having an opening 35provided with an internal right hand thread-. A screw 36 having a righthand threaded portion 37 passing through the opening 35 in the block 34and a left hand threaded portion 38 passing through the opening 33 inthe block 32 tends to rock'tlie links 25 towards and away from means ofrods 40 extending from a block 41' centrally located on the screw 36.In-

clined faces 43 on the vise sections provide conduit sections.

355 will now describe.

means for holding same open to receive the Due to-the right and lefthand threaded portions 37 and 38 of the screw 36 the links can beoperated to accommodate various sizes of-conduit sections28, (seeFig. l)and due to the pivotal mounting of the links 25 upon which the said vicejaws or sections are mounted the vertical center line of the saidconduit sections can be brought into alinement with the rest of themachine which I Secured to the base 20 is a bearing bracket 45 providedwith a central bore46 whose horizontal center line coincides with thehorizontal center line of the vice jaws 27. Mounted within the said bore46 is a bushing 47 in which there is rotatably mounted a hollow sleeve48 which has secured thereto at the end opposite the bracket 45 ashouldered cap or pulley 49 by means of screws 50. The

'sleeve 48 is provided intermediate its ends with a threaded portion 51upon which is screw-threadedly maintained a disc 52 provided with setsof holes v53-54 and 55 to hold tools 56 for reforming the tenon end 57of four inch, three and one-half inchand three inch conduit sectionsrespectively. The said disc 52 is likewise provided with sets ofopenings 58, 59 and 60 to receive the said tools for reforming themortise end 61 of such conduit sections.

The disc 52 carrying the tools 56 is rotated by means of a handle 62secured to one end of a shaft 63 the opposite end of which is secured to,the cap 49. The said cap 49 at its largest portion 64 is of sufficientdiameter to enter the'internal bore 65 of a three inch conduit sectionso as to centralize same with the remainder of the machine. 7 In orderto perform this function withrespect to conduits 72. A key 73provides-additionalsecuring means between the said parts. A hand wheel74 is secured to the bushing 72 by means of a key 75 so that the hollowshaft may be rotated by the rotation of the hand wheel 74. A spacing capis screw threadedly maintained on the bushing 47, between the bracket 45and the hand wheel 74.

Located within the hollow shaft 48' is'a long nut 76 provided with aninternal worm thread 77 with which there engages the exteriorly wormthreaded portion 78. on the hollow shaft 70. The nut 76 has a reducedscrew threaded portion 79 .which screws into an auxiliary nut 80 fast tothe sleeve 48 and in engagement with an enlarged shoulder 81 on the mainshaft 63, the said portion 81 being held by the nut 80 against the wormnut 76. To prevent the worm nut from rotating I slidingly secure same toa bushing 83 by means of a screw 82 extending into a keyway 82a in thesaid bushing 83 which is provided with a slot 84 through which passesascrew suring a perfect alinement of the conduit sec tion with the saidcutting tools.

A frame 88 is screw-threadedly maintained on the bushing 47 and hassecured thereto one; end of spacer rods 89, the opposite reduced ends 90of which are driven into openings in a fiat ring 91 which is adapted toabut and act as a backing for all sizes of conduit sections and stillpermit the tools to pass therethrough. V 7 v Fromthe foregoing it willbe seen that the rotation of the shaft 63 produces a rotary movement ofthe cutting tool disc and the IQ-.' tation of the feed wheel produces afeed movement ofthe said disc and tools, so that the said feedingmovement is entirely independent of the rotary movement of the tools.

In Figures 4, 5 and 6 Ihave shown a modified form of my inventionwherein I provide means by which the feeding of the tools may beaccomplished simultaneously with their rotation. To accomplish this themain shaft 63 is provided, with a keyway 95 and has a worm gear 96 keyedthereto and fastened against lateral movement by a set screw 97.

bearings 100 and has secured thereto the operating handle 62. Adjacentthe worm gear 96 there is keyed to the shaft 63 an eccentric 101 whichis spanned by a forked lever 102 which is secured by screw bolts 103 toa flat strip 104 slidably mounted in a bracket .105

secured to the bearing bracket 45. Pivotally mounted on the said strip104 as at 106 is a pawl 107 which is in engagement with a toothedratchet wheel 108 which is mounted on the bushing 71 in exactly the samemannor as the hand wheel 74 and which it replaces in this form of myinvention.

Normally the pawl 107 is held in engagement with the ratchet 108 bymeans of a spring 109 suspended from an ear 110 on the said pawl andanchored to a stud 111 secured to the lower part of the pawl supportingstrip 104. However, the said pawl 10'? may be brought out of engagementwith the ratchet by swinging same into the dot and dash position Figure4 and kept in said position by inserting a rod through an opening 112 inthe upper portion of the pawl 107 and through an opening 113 in theupper portion of the flat strip 104. (See Figure 4.)

In the normal arrangement of parts the shaft 99 is rotated by the handle62 thus imparting rotary movement to the shaft 62 and eccentric 101through the worm and worm wheel 98 and 96. It will therefore be seenthat upon a complete rotation of the shaft 62 the ratchet wheel 108 willhave been rotated through an angle equal to the distance between tworatchet teeth and imparting a predetermined amount of feeding movementof the tool carrying disc. However by disengaging the pawl from theratchet wheel, the said wheel may be rotated by hand through an anglegreater or less than the distance between two ratchet teeth.

From the foregoing it will be seen that with the modified form of myinvention I may feed the tools simultaneously with the rotating movementor independently therefrom.

It will be understood that the damaged tenon or mortise end is first cutoff and the conduit section is then clamped in the vise jaws, afterwhich the machine is operated to cut a groove G (see Figure 9) in theremaining portion of the conduit section to the required depth afterwhich the remaining corners are cut off by any means available.

It will therefore be seen that I have provided a simple yet efficientportable machine for accurately reforming in the field the tenon ormortise ends of conduit sections.

Having described my invention what I claim as new and desire to secureby Letters Patent is:

1. In a machine for reforming either end of a conduit section providedwith a mortise end and a tenon end and a bore concentric with the saidends, a rotatably and slidably to'the said shaft, means on the saidshaft for engaging the conduit bore, a tool. carrying holder secured tothe said sleeve, meansv for rotat ng "t e said tool holder, means formoving the said tool holder towards and away from the said conduitsection, and a vise fo clamping the said section concentrically with theorbit of the tool. Y

2. In a machine for reforming either end of a conduit section providedwith a mortise end and a tenon end and a bore concentricxwith the saidends, a. rotatably and slidably mounted main shaft, a hollow sleevesecured to the said shaft, means on the said shaft for engagingtheconduit bore, a tool carrying holder secured to the said sleeve, aninternally worm threaded nut operatively maintained within the said"sleeve, a hollow shaft on the main shaft, an external worm'thread onthe said hollow shaft inengagement with the thread in the nut, means forholding the nut against rotation, means for rotating the hollowshaftwithin the nut, means for rotatably connecting the main shaft tothe nut, and means for rotating the main shaft. 6

v 3. In a machine for reforming either end of a conduit section providedwith .a mortise end and a tenon end and a bore concentric with the saidends, .a rotatably and slidably mounted main shaft, means on the saidshaft for engaging the conduit bore, a hollow sleeve secured to the saidshaft, .a tool carrying holder secured to the said sleeve, an internallyworm. threaded nut operatively maintained within the said sleeve, ahollow shaft on the main shaft, an external worm thread on the saidhollow shaft in engagement with the thread in the nut, means for holdingthe nut against rotation, means for rotating the hollow shaft withinthe. nut, means for connectin g the main shaft to the nut, means forrotating the main shaft, and an abutment against which the end of theconduit section being reformed is held.

4. In a machine for reforming either end of a conduit section providedwith a mortise end and a tenon end and a bore concentric with the saidends, a rotatably and slidably mounted main shaft, a hollow sleevesecured to the said shaft, means on the said shaft for engaging theconduit bore, a tool carrying holder secured to the said sleeve, aninternally worm threaded nut operatively maintained within the saidsleeve, a hollow shaft'on the main shaft, an external worm thread on thesaid hollow shaft in en agement with the thread in the nut, means orholding the nut against rotation, a drive shaft, a worm thereon, a wormgear on the main shaft in mesh with the worm, means for connecting themain shaft to the nut an eccentric keyed to the main shaft, a slidablepost, an arm secured to the post and in operative engagement with theeccentric, a toothed ratchet wheel secured to the hollow shaft, and aspring pressed pawl pivoted on the slidable post and normally inengagement, with the ratchet wheel to rotate the hollow shaft in the nutto feed the said 4, nut and tool carrying sleeve towards the conduitsection end to be reformed.

5. In a machine for reforming either end of a conduit section providedwith a mortise end and a tenon end and a bore concentric with the saidends, a rotatably and slidably mounted main shaft, a hollow sleevesecured to the said shaft, means on the said shaft for engaging theconduit bore, a tool carrying holder secured to the said sleeve, aninternally worm threaded nut operatively maintained within the saidsleeve, a hollow shaft on the main shaft, an external worm thread on thesaid hollow shaftin engagement with the thread in the nut, means forholding the nut M against rotation, a drive shaft, a vworm thereon, aworm gear on the main shaft in mesh with the worm, means for connectingthe main shaft to the nut an eccentric keyed to the main shaft, aslidable post, an arm se- A cured to the post and in operativeengagement with the eccentric, a toothed ratchet wheel secured to thehollow shaft, a spring pressed pawl pivoted on the slidable post andnormally in engagement with the ratchet wheel .7, to rotate the hollowshaft in the nut to feed the said nut and tool carrying sleeve towardsthe conduit section end to be re-' formed, and means whereby the pawlmay be held out of engagement with the ratchet.

In testimony whereof I hereunto afiix my signature.

ALBERT E. MITCHELL.

